I go to Uni on Saturday and I really don't want to go but I've already taken a gap year and wasted it, Any advice?

I am 19 and I am starting University next week but I really don't want to go. I took a gap year because I didn't want to do a Foundation year course because it puts me in £15k debt before I've even started my degree but with the grades I got in my BTEC diploma I have to do a foundation year. The BTEC course I did is the biggest regret of my life because if I go to University then Engineering is the only thing I can do but I'm terrible at Maths (I got a C in my Maths GCSE although according to my teacher should have been higher, this is the reason I did the BTEC). I either have to go to University Saturday or I take another Gap year which won't look good on my CV after what the gap year I've just taken entailed (sat in my room feeling sorry for myself for the first 5 months then struck up enough courage to change something and joined a gym, been going 4 days a week since). I worked part time on my dads farm and have been basically relying on him for everything which makes me feel sick. I have no friends and the only reason I'm thinking of going to university is to meet new people but is meeting new people worth £15k of debt, probably not.

I haven't even opened a student bank account because I'm so unsure of what to do. If I take another gap year I have been thinking about taking an acting class to help improve my confidence. Can someone please give me some advice because I have no one else to talk to and I am freaking out like crazy! Thank you for reading this far